Piezoelectric devices can be used to produce electrical power when attached to a source of vibrations such as a motor, machine, or the like. The power produced can be used, for example, to power a microcontroller, transmitter, and a sensor. See the data sheet for the Mide Volture™ piezoelectric “Energy Harvester” product incorporated herein by this reference. In this way, the temperature of a motor can be sensed, reported, and monitored without the need for a battery which requires replacement.
Still, there is a need to sense additional parameters using battery-less systems. It is known, for example, to use an accelerometer or microphone to sense vibrations but such devices add to the cost of the system and also consume additional power.